Question

Why can’t a laboratory thermometer be used to measure body temperature

Answer 1

because laboratory thermometer allow to fall down the mercury which the clinical thermometer doesn't allow as it has kink and the clinical thermometer does not more than 100 degree Fahrenheit temperature.

Answer 2

"Generally the laboratory thermometer have the range from -10˚C to 110 ˚C . So it has a wider range of degree. So it does not give the accurate measurement.

Whereas the "thermometer used to measure" body temperature is "extremely accurate" over an extremely small range of temperatures. It will give the "temperature to the tenth" of a degree. While humans have normal body temperature in the range of 37˚C to 38˚C "